The present disclosure relates generally to drilling of wells. More particularly, the present disclosure relates to methods and apparatus for cleaning, lubricating and testing pipes.
At some point during the drilling of a well, there will be a reason to pull a drill string out of a well and then run it back in. This process is typically referred to as “tripping.” The portion of the tripping involving pulling the drill string out of the well may be referred to as “tripping out,” and the portion of the tripping involving running the drill string back into the well may be referred to as “tripping in.” Tripping out involves breaking out pipe connections, whereas tripping in involves making up pipe connections. On some rigs, the breaking out and making up of pipe connections are between single drill pipes, as opposed to pipe stands, and a drill string.
During tripping out, the drill string is suspended in the well in slips. An elevator picks the drill string up from the slips and raises the drill string until a drill pipe at the top of the drill string is just above the slips. The slips then close. An iron roughneck is used to spin the drill pipe and break out the connection between the drill pipe and the drill string. A pipe handling system picks up the drill pipe, disconnecting the elevator from the drill pipe. The pipe handling system moves the drill pipe to a horizontal position on the ground. A forklift then picks the drill pipe from the pipe handling system and places the drill pipe in a horizontal rack on the ground. This process can be repeated for as many drill pipes as need to be separated from the drill string. The separated drill pipes can be arranged in multiple horizontal racks on the ground.
Tripping in starts with the drill pipes stored in horizontal racks on the ground. While the drill string is suspended in slips, a worker lubricates a box at the top of the drill string. A forklift moves a drill pipe from one of the horizontal racks to the pipe handling system, and the pipe handling system in turn moves the drill pipe to the well center. At the well center, an elevator picks up the drill pipe and stabs the drill pipe into the box. After the stabbing, an iron roughneck spins the drill pipe and makes up the connection between the drill pipe and the drill string. The elevator then lifts the drill string from the slips and lowers the drill string until the drill pipe is just above the slips. The slips close, and the elevator is disconnected from the drill pipe. This process can be repeated for as many drill pipes as need to be connected to the drill string.
In some cases, prior to connecting a drill pipe to the drill string, the pin and box of the drill pipe are cleaned. Typically, this cleaning is carried out while the drill pipe is in the vertical position. The cleaning of the drill pipe and lubrication of the box prior to making up the pipe connection lengthen the duration of the tripping in. Also, the vertical orientation of the drill pipe during the cleaning as well as time constraints on rig operations can make it difficult to achieve quality pipe cleaning and lubrication.